Field of the Disclosure
Embodiments of the present invention relate to an apparatus and method of manufacturing a graphene film, and more particularly, to an apparatus and method of manufacturing a graphene film capable of flattening wrinkles.
Discussion of the Related Art
Fullerene, carbon nanotube, graphene, and graphite are known as a material comprised of carbon atoms. Graphene is a conductive material having a structure in which carbon atoms are arranged in a honeycomb shape on a two-dimensional plane.
Graphene is structurally and chemically very stable. Also, graphene is a good conductor capable of transferring an electron more rapidly in comparison to silicon, and also enabling more current flowing in comparison to copper. Also, graphene has transparency and nano pattern so that it enables an easy processing. Accordingly, it has been tried to apply graphene having the aforementioned many advantages to a sensor, a memory, and a flat display device.
In order to apply graphene to various fields, a method of mass synthesis of graphene is necessary. A related art thin graphene film is obtained through the following processes: graphite is ground mechanically, the ground graphite is dispersed in a solution, and then a thin film of graphene film is synthesized by a self-assembly phenomenon. In this case, it is difficult to satisfy a desired level of the electrical and mechanical properties in the obtained graphene film.
Accordingly, the present applicant proposed a method of synthesizing a graphene film on a metal catalyst base by a chemical vapor deposition method, and also proposed a method of forming a graphene film on a desired substrate.
FIGS. 1A to 1E illustrate a process of forming a graphene film on a desired substrate proposed by the present applicant.
First, as shown in FIG. 1A, a graphene film 2 is deposed on an upper surface of a metal catalyst base 1 by a chemical vapor deposition method.
Then, as shown in FIG. 1B, a support substrate 3 is deposited on an upper surface of the graphene film 2.
As shown in FIG. 1C, the metal catalyst base 1, which is provided on a lower surface of the graphene film 2, is removed by etching.
Then, as shown in FIG. 1D, a target substrate 4 is deposited on the lower surface of the graphene film 2 from which the metal catalyst base 1 is removed.
Then, as shown in FIG. 1E, the support substrate 3 is separated (peeled-off) from the upper surface of the graphene film 2, to thereby obtain the graphene film 2 formed on the desired target substrate 4.
In case of the above method shown in FIGS. 1A to 1E, the graphene film 2 is formed on the finally-desired target substrate 4 through the deposition process of the graphene film 2 by the chemical vapor deposition method, the etching process of the metal catalyst base 1, the deposition process of the target substrate 4, and the separation process of the support substrate 3.
This method inevitably includes the process of depositing the graphene film 2 on the metal catalyst base 1, which may cause the following problems.
As shown in an expanded view indicated by an arrow of FIG. 1A, after the graphene film 2 is deposited on the metal catalyst base 1, wrinkles may be generated in a lamination structure of the metal catalyst base 1 and the graphene film 2. The lamination structure with the wrinkles may be obtained by depositing the graphene film 2 on the metal catalyst base 1 with the previously-generated wrinkles. Or, the lamination structure with the wrinkles may be obtained by the wrinkles generated in the metal catalyst base 1 for the process of depositing the graphene film 2 at a high temperature or the following treatment process after the deposition process of the high temperature.
If the wrinkles are generated in the lamination structure of the metal catalyst base 1 and the graphene film 2, as shown in an expanded view indicated by an arrow of FIG. 1C, after the process of etching and removing the metal catalyst base 1 from the lower surface of the graphene film 2, there may be a void defect area 2a in the graphene film 2, or an overlap defect area 2b whose thickness is uneven due to an overlapped portion of the graphene film 2. Accordingly, as shown in an expanded view indicated by an arrow of FIG. 1E, the void defect area 2a or overlap defect area 2b remains in the graphene film 2 formed on the finally-obtained target substrate 4.
If the void defect area 2a or overlap defect area 2b remains in the graphene film 2 formed on the finally-obtained target substrate 4, it is difficult to realize uniformity in the graphene film 2. As a result, the properties of surface resistance in a device with the graphene film 2 may be lowered, and device reliability may be degraded due to permeation of oxygen or moisture into the void defect area 2a. 